The Pentagon knows that sometimes, time really is of the essence. That’s why they are throwing their weight behind a new aircraft tested on Tuesday — one capable of traveling six times the speed of sound for minutes on end.

The X-51A Waverider, an unmanned experimental aircraft being financed by both the US Department of Defense and NASA, was tested over the Pacific Ocean on Tuesday. The Los Angeles Times reported that travelling through the sky at Mach 6 — or roughly 4,300 miles per hour—for just around five full minutes would be twice as long as any other hypersonic aircraft has sustained before. If all goes as planned the Pentagon may be one step closer to ushering supplies, missiles, and one day even passengers across the Atlantic, all in under an hour.

"Attaining sustained hypersonic flight is like going from propeller-driven aircraft to jet aircraft," Robert A. Mercier, deputy for technology in the high speed systems division at the Air Force Research Laboratory in Ohio, told the Times. "Since the Wright brothers, we have examined how to make aircraft better and faster. Hypersonic flight is one of those areas that is a potential frontier for aeronautics. I believe we're standing in the door waiting to go into that arena."

Graphic shows the X-51A Waverider as it is set to demonstrate hypersonic flight (AFP Photo / US Air Force)

The flight plan had the test aircraft being lifted by a B-52 bomber to an altitude of 50,000 feet over the Pacific Ocean. The remotely piloted craft was then to be dropped from the bomber into a short freefall.A jet engine ignites, propelling the test craft to speeds of mach 4.5. Afterwards, that engine is jettisoned and the Waverider’s new scramjet takes over, sucking oxygen and propelling the craft to staggering speeds of 4,300 miles per hour – approximately six times the speed of sound. The new scramjet engine is unique, allowing the craft to essentially ride the shockwaves created by its own flight, earning it the nickname “Waverider”. The test craft was designed to fly at those speeds for approximately 300 seconds before breaking up over the Pacific in a watery demise.

"The X-51 is not retrievable, in other words once you fly it, it's going to end up in the ocean," said John Haire, spokesman for the 412th test wing at Edwards Air Force Base in California. The test results are scheduled to be published on Wednesday.

graphic shows The X-51A Waverider, under the wing of a B-52 Stratobomber set to demonstrate hypersonic flight (AFP Photo / US Air Force)

But of course, the Pentagon is still developing its hypersonic technology for practical use. The test flight last year of its infamous “X-plane”, designed to fly at a whopping Mach 20 (approximately 15,000 miles per hour, or 20 times the speed of sound) also ended at the bottom of the Pacific, much to the chagrin of its designers. Although engineers know this Waverider flight is a one-way ticket, the Pentagon is hoping for better results; the last time the Waverider took to the skies, the craft only flew 143 seconds before crashing into the ocean.

Following the failed X-plane mission, Defense Advanced Research Projects Agency director Regina Dugan issued a statement saying that data from that attempt will give the Pentagon “a better understanding of overall system capability and flight dynamics — how far it can fly with more accuracy."